Smartphone technology is always marching forward, progressing rapidly with new hardware improvements with each iteration and model revision.

Faster processors, infinity displays, better cameras, waterproofing, facial recognition - the list goes on. But what's the use of having all these fancy features if your smartphone battery can't even last through a full day?

Thankfully, smartphone makers are already making strides in improving battery life. How? By optimizing software and by sticking in a bigger battery, of course.

Here's our list of the best smartphones that can last you for a full a day and more with just a single charge.

iPhone 8 Plus

The iPhone 8 Plus may not have the largest iPhone battery around but it has the longest battery life among the current crop iPhones, trumping even the iPhone X.

It's likely due to its smaller LCD screen and hardware/software optimizations that pushes it ahead of Apple's flagship smartphone.

The iPhone 8 Plus can last up to 13 hours of internet use compared to 11 hours on the iPhone X. This means it typically lasts a full day of heavy use on a single charge. And like the iPhone X, the iPhone 8 Plus (and the iPhone 8) also supports quick charging and wireless charging.

Razer Phone

The Razer Phone is a premium Android smartphone meant for high performance gaming on the go. As such, it has fancy buzzwords typically meant for the home theater - high-end Dolby Atmos sound, a 120Hz ultra-motion screen and support for Netflix's 4K HDR and Dolby Digital Plus formats.

Powering all this goodness is a large 4,000mAh battery. However, to take advantage of this extra juice, you'll have to tone some of its nicer features down a bit. Limit its display refresh rate down to 60Hz and you can squeeze out around two days of normal usage out of this beast.

Cat S61

When it comes to ruggedness and durability, CAT is making a name for itself with its line of shock-resistant, dust-resistant and waterproof Android smartphones.

While its flagship CAT S61 smartphone boasts unique features like a thermal imaging camera, a laser assisted distance measuring tool and a built-in indoor air quality monitor, it also has a big 4,650mAh to juice it all up.

With this kind of power, this smartphone can last around two days of normal usage on a single charge.

The CAT S61 may not come cheap at around $999 but it has many functions that you can't find on any other smartphone. It's certainly worth a serious look.

Moto E5 Plus

Don't let the Moto E5 Plus' bargain bin price fool you, it has a massive 5,000mAh battery, one of the largest ones around. This can definitely last you for around around a day and a half of heavy use.

It also supports quick charging so you can top it off with extra hours of usage with just 15 minutes of charging.

The Moto E5 Plus other specs are decent too - a large 6-inch HD display, 12MP rear and 8MP front cameras, 3GB of RAM and 32GB of storage.

Blackberry Key2

If you fancy having a good old hardware QWERTY keyboard on your phone, with a superior battery to boot, then the Blackberry Key2 is worth a look.

Although it carries the Blackberry pedigree, the Blackberry Key2 is actually manufactured by TCL under the name "Blackberry Mobile."

The Key2 is an Android handset rocking a powerful quad-core Snapdragon 660 processor juiced up by a large 3,500mAh battery, enough to run it for around 25 to 35 hours before charging. It also has Qualcomm Quick Charge 3.0 support, good for squeezing hours of use with just 15 minutes of charge time.